Aircraft clock



April 1962 c. L. LOVERCHECK 3,030,765

AIRCRAFT CLOCK Filed Jan. 26, 1959 INVENTQR. CHRRLEG L. LOVERCHECK United States Patent 3,030,765 AIRCRAFT CLOCK Charles L. Lovercheck, 632 W. 7th St., Erie, Pa. FiledJan. 26, 1959,-Ser. No. 788,840 6 Claims. (Cl. 58-152) This invention relates to clocks and, more particularly, to clocks for use on aircraft.

During instrument flying, it is frequently necessary for the pilot to control his aircraft in the vicinity of a given location for a period of time in a holdingpattern. These holding patterns are usually carried out over a radio station, the radio station being directly under one point in the path of the pattern. The pilot commences a procedure turn to the right of one hundred-eighty degrees per minute 'at'the radio station. After a turn of one hundred eighty degrees, the pilot flies straight and level for two minutes, then starts another procedure turn at the rate of one hundred eighty degrees a minute, and flies two minutes straight ahead after the procedure turn 'back'to the radio station. He then turns again and thus starts another holding pattern. These holding patterns are in the shape of a race track and are frequently designated race track holds. Some short holding patterns are like the long patterns but involve a straight flight of one minute after each turn instead of two, thus resulting in a total of four minutes for the pattern.

With clocks now in use, a pilot must remember what time he has started his turn and what time the turn has ended and, also, determine how long he'has flown straight ahead, whether it is one minute, two minutes, or three minutes by referencetoan ordinary clock. This requires memory and calculation 'on the part of the pilot, often at a time when 'his attention is needed elsewhere.

It is, accordingly, an object-of this invention 'to provide aclock which will indicate the time that an aircraft has flown in a holding pattern.

Another object of the invention is to provide an improved aircraft clock.

A further object of the invention is to provide an aircraft clock having a rotatable dial on the face thereof with a holding pattern inscribed therein and a hand which will travel at the rate of six minutes per revolution and an alternate travel of four minutes per revolution over the dial, the dial being rotatable to align the holding pattern thereon with any bearing of a compass rose supported on the outside thereof.

A still further object of the invention is to provide an aircraft clock which is simple in construction, economical to manufacture, and simple and efficient in operation.

With the above and other objects in view, the present invention consists of the combination and arrangement of parts hereinafter more fully described, illustrated in the accompanying drawing and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportions, and minor details of construction without departing from the spirit or sacrificing any of the advantages of the invention.

In the drawing:

FIG. 1 is a view of a face of a clock according to the invention;

FIG. 2 is a diagrammatic view of the internal workings of a clock having the face shown in FIG. 1; and

FIG. 3 is a cross sectional view of the face shown in FIG. 1.

Now with more specific reference to the drawing, a clock is shown having a face 11. The face 11 is fixed to the clock frame and will be anchored to the panel of an aircraft. Numerals on a surface 12 of the face 11 indicate the twelve hours of the day and numerals on a 3,030,765 Patented Apr. '24, "1962 surface 13 ofthe-fixed face 11 indicate the three hundred sixty degrees of the ordinary compass rose. Both the surface -12 and the surface 13 are annular and have an opening in the center which receives a rotatable flight path disk 14.

The flight path disk 14 has an outwardly extending rim having gear teeth 28 around the outer periphery thereof whichmesh with a gear29. The gear 29 may be rotated by means of a suitable handle 17 for rotating index marks 5St'o align them with the pattern heading and thusalign the major axis of the pattern with the desired bearing. The central aperture in the disk 14 rides on a flight pattern sleeve 46.

Arace track shaped holding pattern isinscribed on the center of the disk 14 in the shape of a standard race track holding pattern. It has turning points 24 inscribed at the four points thereon. The clock 10 has 'a flight pattern-hand 23 which rotates at the rate of four minutes or six minutes per revolution. The flight pattern hand 23 has around disk 59 on theend thereof which-overlies the points 24 four times each revolution to give the pilot a definite indication of when time has arrived for the aircraft :to be "at a turning point.

A winding knob 15 is provided for the clock 10 for wi-ndingand a knob 16'is provided for setting theclock 10 in the conventional manner if it is a mechanically driven clock. A power source which may be a spring motor as indicated at 26 drives through the drive shaft 'to a shaft 27, agear39, and a gear 36.

A second hand 2t) is driven by a shaft 37 from gears 33 and39 and the shaft 27 connected to the power source 26. A minute hand 21 isdriven by a shaft 40, gears 41 and 42, a shaft 43', gears 44-and 45, the shaft 37, the gears 38 and 39, and the shaft 27 connected to the power source 26. I

An hour hand 22 is driven by'a "shaft 34 and gears 35 and 36 connected to the shaft 27 which is connected to the power source 26.

The hand '23 is driven at the rate of six minutes per revolution when a gear 47 attached 'to a shaft 46 is in mesh withagear 48. Gears 48, 51, and'55 are fixed to a shaft 54. The shaft 54 with the gears 48, 51, and 55 thereon may be shifted by a shifting lever 33 connected to a selector knob 19 to bring the gear 48 out of engagement with the gear 47 and to engage the gear 51 with a gear 50, thereby driving the hand 23 at the rate of four minutes per revolution.

The power to drive the hand 23 starts at the power source 26 connected to the shaft 27, gears 39 and 38, shaft 37, gears 45 and 44, shaft 43, and gears 42, 41, and 55. The shifting lever 33 shifts from a neutral position to engage the gear 43 or the gear 51 with the gear 47 or 50, respectively. The gears 50 and 47 are fixed to the shaft 46.

The hand 23 may be set at one of the turning points 24 by a knob 18 connected to a gear 56 and the gear 47. The gear 56 rotates about a shaft 25.

A gear 49 meshes with the gear 48 in one position. When the lever 33 is set to drive the hand 23 at four minutes per revolution, the gear 51 meshes with a gear 52. A shaft 53 will be driven at the same rate that the hand 23 is driven by the gear .51 which will then mesh with the gear 52. The shaft 53 is connected to the gears 49 and 52 and to cams 31 and 30. The cams 31 and 30 have detents thereon which engage an alarm contact 32 which may be connected to a suitable bell or light so that a signal will be given each time the hand 23, which is connected to the same point on the path of rotation as the detents on the earns 30 and 31, reaches one of the points 24 of the holding pattern. When the lever 33 is set for six minutes, the contact 32 will be set to engage the cams 31. Therefore, the signalwill be given by the contact 32 each time the hand 23 reaches a point 24. Therefore, a visual as well as an audible signal may be given to the pilot so that he will know when to begin his procedure turn. The contact 32 will be moved to engage the cam 30 when the gear 51 engages the gear 50.

It will be seen that when the pilot wishes to start the holding pattern, he can rotate the indicating disk 14 to bring the marks 58 to the bearing on the compass rose on the surface 13 corresponding to the bearing of the holding pattern. Then he can set the hand 23 over one of the points 24 at the corresponding position to the radio station. The points 24 are referred to herein as critical points. The pilot can then start the hand 23 by shifting the lever 33 to bring either the gear 48 or the gear 51 into mesh as his aircraft passes over the holding pattern. He can then start his procedure turn each time the hand 23 passes over one of the points 24 and stop the turn after it passes over the next point 24, thereby following his holding pattern with precision.

The foregoing specification sets forth the invention in its preferred practical forms but the structure shown is capable of modification within a range of equivalents without departing from the invention which is to be understood is broadly novel as is commensurate with the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A clock for use in an aircraft comprising a conventional clock face having a minute hand, a second hand, and an hour hand thereof, a hand on said clock, means to rotate said hand on said clock selectively at six minutes or at four minutes, an oval or race track shaped pattern on said clock face, said race track shaped pattern having two semi-circular portions separated by two linear portions, and a designation at the juncture of each said linear portion with each said semi-circular portion, said six minute and four minute hand having an end thereon overlying one said designation each time said hand reaches one said designation.

2. A clock for use in an aircraft comprising a conventional clock face having a minute hand, a second hand, and an hour hand thereof, a hand on said clock, means for rotating said hand on said clock selectively at six minutes or at four minutes, an oval or race track shaped pattern on said clock face, said race track shaped having two semi-circular portions separated by two linear portions, a designation at the juncture of each said linear portion with each said semi-circularportion, said'six minute and four minute hand having an-end thereon overlying one said designation each time said hand reaches one said designation, a rotatable disk, said race track shaped pattern being inscribed on said rotatable disk supported on the central portion of the face of said clock, a compass rose disposed around said disk, and means to rotate said disk to align the major axis of said race track shaped pattern with a predetermined bearing of said compass rose.

3. The clock recited in claim 2 wherein means is provided to selectively shift said means for rotating said six minute hand to a position to rotate it at four minutes per revolution. 4. The clock recited in claim 1 wherein signal means is provided operable each time said six minute hand passes a predetermined point on said race track shaped pattern.

5. The clock recited in claim 1 wherein means is provided to set said six minute hand independent of said hour hand, said minute hand, and said second hand.

6. The clock recited in claim 5 wherein means to start said six minute hand is provided independent of said hour hand, said minute hand, and said second hand.

References Cited in the file of this patent UNITED STATES PATENTS 505,687 Watts Sept. 26, 1893 1,131,498 Emery Mar. 9, 1915 1,367,148 Kennedy Feb. 1, 1921 2,289,038 Putnam July 7, 1942 2,296,540 Schurz Sept. 22, 1942 2,543,032 Laviana Feb. 27, 1951 2,551,100 Davis May 1, 1951 2,576,452 Field et a1. Nov. 27, 1951 2,667,921 Doyle Feb. 2, 1954 FOREIGN PATENTS 235,072 Switzerland Feb. 16, 1945 297,904 Switzerland June 16, 1954 

